Photocatalytic degradation phenomena of methylene blue dye by ZnFe2O4 decorated with rGO nanocomposites under visible light irradiation

Abstract

Recent advancements in photocatalytic technologies have opened sustainable pathways for the removal of organic pollutants from wastewater. In the present study, a reduced graphene oxide (rGO)-modified ZnFe₂O₄ (rGO-ZFO) nanocomposite was successfully synthesized using a simple solution combustion method to improve charge separation efficiency and enhance visible-light-driven photocatalytic activity. The synthesized materials were characterized by XRD, FTIR, SEM, TEM, UV-Vis, and PL analyses, which confirmed the successful incorporation of rGO into the ZnFe₂O₄ matrix. The modification led to enhanced crystallinity, suppression of charge carrier recombination, and a reduction in band gap energy. These improvements significantly contributed to the superior photocatalytic performance of the rGO-ZFO composite, achieving 93 % degradation of methylene blue under visible light within 180 min. Furthermore, scavenger experiments identified the major reactive species involved in the degradation pathway, providing deeper insight into the underlying mechanism. This study establishes a clear structure-property-performance correlation and highlights that rGO incorporation effectively optimizes the electronic and surface characteristics of ZnFe₂O₄, rendering it a promising, eco-friendly, and efficient photocatalyst for wastewater treatment applications.